Abstract:A borate ester bonding agent with a five-membered ring was synthesized via a "one-pot" process using borate acid, ethylene glycol and 1, 2, 4-butanetriol as raw materials. Its structure was characterized by FTIR, ¹¹B NMR, ¹H NMR and MS. The hydrolysis reaction kinetics of the synthesized borate ester in normal temperature water and in saturated water vapor was investigated by an on-line IR analysis method. The hydrolysis reaction kinetic model was established. The results show that the hydrolysis of the synthesized borate ester under above-mentioned two conditions is the pseudo-first order reaction. The reaction rate constant and half life of the borate ester are 2.3×10^-5 s^-1 and 8.4 h in normal temperature water, 2.96×10^-7 s^-1 and 27 d in saturated water vapor, respectively. The addition of 0.2% borate ester makes the tensile strength of RDX/HTPB explosive increase from 0.80 MPa to 1.44 MPa and the compressive strength increase from 5.04 MPa to 13.27 MPa, proving that the synthesized borate ester has good bonding effect.

Abstract:A high energetic oxidizer N-oxides of 3, 3′-azo-bis(6-amino-1, 2, 4, 5-tetrazine)(DAATO_3.5) was synthesized via the two-step oxidation reactions of potassium permanganate and hydrogen peroxide/trifluoroacetic anhydride, using 3, 6-diamino-1, 2, 4, 5-tetrazine as starting material. The total yield of DAATO_3.5 was 53.1%. Its structure was characterized by FT-IR, NMR and elemental analysis. The reaction mechanism for H₂O₂/ (CF₃CO)₂O oxidation was studied. The optimum conditions of the reaction were determined as: 3, 3′-azo-bis(6-amino-1, 2, 4, 5-tetrazine)(DAAT)/(CF₃CO)₂O/H₂O₂=1/12.5/11 (molar ratio), reaction time, 20 h and reaction temperature, 20~25 ℃. The thermal behavior of DAATO_3.5 was studied by DSC and TG-DTG. Results show that DAATO_3.5 has an exothermic decomposition peak at 254.6 ℃, indicating a better stability. The main properties of DAATO_3.5 was tested and followed as: density 1.840 g·cm^-3, friction sensitivity 100%(90°), impact sensitivity 100%(10 kg, 25 cm).

Abstract:With glyoxal, methylhydrazine and hydroxylamine hydrochloride as starting materials, 2-methyl-4, 5-dinitro-1, 2, 3-triazole-1-oxide(DNMTO) was synthesized by the process of condensation, oxime, cyclization and nitration with yield of 16% and purity of 99%, and title compound and its intermediate were characterized by IR, ¹H NMR and elemental analysis. Compared with the four-step reaction in the literature, this approach was reduced to two steps. The optimum conditions for the cyclization and nitration reaction were as follows: reaction temperature was 100 ℃ and reaction time was 0.5 h. The structure of DNMTO was also estimated by a B3LYP method based on aug-cc-pVDZ basis set and the stable geometric configuration and bond order were obtained. The relationships between temperature and thermodynamics properties were confirmed. The results show that all thermal energy, thermal capacity and entropy increase with the increase of temperature.

Abstract:5-Aminotetrazolium nitrate(5-ATN) was synthesized from 5-aminotetrazole monohydrate(5-AT·H₂O) and concentrated nitric acid. The effects of nitric acid dosage, reaction time and reaction temperature on the yield of 5-ATN were discussed. The proper synthesis conditions determined by orthogonal experiments were as follows: 5 g 5-AT, 15 mL nitric acid, reaction temperature 20 ℃ and reaction time 15 min, with the yield of 92.6%. Compared with previous studies, the reaction temperature and reaction time decrease while the yield is improved. SEM picture shows that the surface of 5-ATN is smooth, and hellogh humidity storage tests show that the water absorption of product is reduced.

Abstract:The decomposition temperatures of composite explosives (HMX+NOG₂Tz) in different mass proportions were measured by differential scanning calorimetry (DSC). The detonation velocities of composite explosives were calculated by an empirical equation. The thermal behavior of the composite explosive 9^# (80%HMX + 20%NOG₂Tz) was studied by DSC at different heating rates. The apparent activation energy and pre-exponential factor of the exothermic decomposition reaction, the temperature (T_e0) of the extrapolated onset in heating rate β→0, and the critical temperature of thermal explosion (T_b) were calculated. The results show that the decomposition peak temperature of the composite explosive 9^# increases by 2 ℃and the apparent activation energy by 70 kJ·mol^-1over the pure HMX. It indicates that the addition of NOG₂Tz (< 50%) can improve the thermal stability of HMX.

Abstract:To study the microstructure of nitrocellulose(NC) aerogel and its relationship with thermal properties, NC aerogel was prepared by sol-gel method and supercritical drying. The microstructure, crystallizability and thermal properties of the aerogel were characterized by SEM, XRD and TG/DSC-FTIR methods. Results show that: the microstructure of NC aerogel is nano-porous structure accumulated by nano-particles. The crystallization of NC is destroyed in NC aerogel, presenting amorphous disordered state. In comparison with NC, the DTG peak temperature and DSC exothermic peak temperature of NC aerogel shift 7 ℃ and 12 ℃ downwards, respectively, and the decomposition heat increases from 1429.87 J·g^-1 to 1689.21 J·g^-1.

Abstract:To explore the thermal stability of 2, 6-diamino-3, 5-dinitropyridine-1-oxide(ANPyO), the adiabatic decomposition process of ANPyO was studied by accelerating rate calorimeter. The decomposition temperature, pressure and temperature rise rate versus time curves, and pressure and temperature rise rate versus temperature curves were obtained. Results show that adiabatic thermal decomposition process of ANPyO can be divided into two exothermic reaction stages. The first stage is the main decomposition one, in that the temperature rise rate has an obvious change. The apparent activation energy, pre-exponential factor and heat of reaction obtained by calculation are 293.61 kJ·mol^-1, 1.515×10²³ min^-1 and 940.92 J·g^-1, respectively. The initial decomposition temperature of ANPyO is higher than 290.8 ℃, showing a better thermal stability.

Abstract:The thermal behavior of guanidinium azotetrazolate (GZT) was studied using the thermogravimetry and differential scanning calorimetry. The thermal decomposition mechanism of GZT was proposed based on the investigation of products in condensed and gas phases by the combination techniques of solid in situ cell with the rapid-scan Fourier transform infrared spectroscopy and pyrolysis-gas-chromatography-mass-spectrometry (Py-GC-MS). Results show the first mass loss process of GTZ includes the exothermic decomposition reaction of azotetrazolate and the endothermic decomposition reaction of guanidinium. Under heating, the intermediate product tetrazoleazide (CHN₇) may forme through the ring-opening reaction of tetrazole on the azotetrazolate molecular and the ultimate products are high boiling point materials: melamine and ammonium azide. Under the bombardment of ion source, the bond C—N_azo on azotetrazolate molecular also split and dissociate in sequence.

Abstract:The crystallization refinement of RDX was performed by the process solution enhanced dispersion technique of supercritical fluids(SEDS) method. Exploring experiments were conducted to determine the DMF as solvent and the concentration of RDX/DMF solution as 20%.The factors affecting the refinement efficiency of RDX were investigated and analyzed via orthogonal L₉(3⁴)test design and single factor experiment. The results show that suitable solvent is the key to avoid obtaining flake or needle-like crystals. The order of factors affecting the effect of crystallization are pressure, CO₂ flow rate, sollution flow rate and temperature. As the fluid density is close to liquid density, the ratio of CO₂ flow rate and solution flow rate is directly related with granular proportion and the particle size, but the concentration determines the particle size ultimately. The expanding process conditions are concentration 26.7%, temperature 35 ℃, pressure 9.0 MPa, solution flow rate 2 mL·min^-1 and CO₂ flow rate 6 kg·h^-1. Under these conditions the edge of fine RDX particles obtained is smooth, and shape nearly spherical. The particle size distribution is uniform between 3~5 μm, and the fine RDX particles have good fluidity and low mechanical sensitivity. Its preparation amount can be up to 32 g·h^-1.

Abstract:The relationship between characteristic parameters of micro-raman spectra and quality of different HMX crystals including single crystal, spherical crystal and industrial crystal was studied. Based on the comparison of peaks of micro-raman spectra, the 951 cm^-1 was determined to be the characteristic peak of HMX crystal. Statistical analysis was used for full width at half maximum (FWHM) of characteristic peak and the relative standard deviation (RSD) of measurements with the results that the FWHMs for single crystal, spherical crystal and industrial crystal were 15.18, 16.71, 17.84 cm^-1, and the RSDs for the three HMX crystals were 0.0143%, 0.0524% and 0.129%, respectively. While, by parallel test at one point for 12 times, the FWHM and RSD for HMX single crystal was 15.18 cm^-1 and 0.0122%. Through matching refractive micrograph and scanning electron microscopy images, the quality order for the three HMX crystals was single crystal > spherical crystal > industrial crystal. So, it can be conclude that the characteristic peak parameters of HMX crystal by micro-raman spectra can be used to evaluate the quality of HMX crystals: the closer the FWHM is to 15.18 cm^-1, the smaller the RSD, and the better the quality of HMX crystals.

Abstract:The thermodynamic data of heat flow curve, heat transfer coefficient and heat capacity in nitration reaction of 2-methylpyrimidine-4, 6-dione in the synthesis of 1, 1-diamino-2, 2-dinitro ethylene(FOX-7) were measured by using reaction calorimeter(RCle). Results show that the average heat release rate of nitration reaction in feeding is about 80W and in the finishing period about 40W. The total exothermic heat of nitration reaction is 375.22 kJ·mol^-1, and the adiabatic temperature rise is 483.8 K. The thermal behaviors of 2-dinitromethylene-5, 5-dinitropyrimidine-4, 6-dione were analyzed by differential scanning calorimeter and thermogravimetry-derivative thermogravimetric analysis techniques. Results show that its thermal decomposition process can be divided into two stages. The initial decomposition temperature is 30 ℃, the peak temperature of first-stage is 67.01 ℃ and the enthalpy of decomposition reaction is 201.2 J·g^-1. The peak temperature of second-stage is 87.15 ℃ and the enthalpy of decomposition reaction is 1046.6 J·g^-1. This indicates that the thermal stability of 2-dinitromethylene-5, 5-dinitropyrimidine-4, 6-dione is bad.

Abstract:Coated RDX were prepared by water suspension coating method, spray coating method and demulsification method, using acrylonitrile-styrene (AS) copolymer, fluoro rubber (F2311), polyurethane elastomer (Estane5701) and waterborne polyurethane (WPU) as coating raw materials, respectively. The high performance liquid chromatography (HPLC) determination of coated particles, quantitative determination of the dissolution quantity of RDX and calculation of the adhesive coated degree of RDX were carried out. The characterization efficacy of HPLC, scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) was compared. Results show that using AS as raw material, the coated particles obtained by spray coating method have dense coating and perfect physical contact with the surface of RDX. The situation of incomplete coating is not detected by EDS. The degree of coverage obtained by HPLC is 96.24%.

Abstract:In order to explore the vulnerability of Comp.B explosive at different temperatures and evaluate the effects of penetration depth and ambient temperature on the reaction level of Comp.B explosive, the armor-piercing incendiary of 12.7mm was used to penetrate Comp.B explosive at a speed of 850 m·s^-1. The response characteristics of Comp.B explosive at -40, 25, 70 ℃ were studied. The processes of bullet penetration were simulated by the non-linear finite element software ANSYS/LS-DYNA and the influences of mechanical properties of Comp.B explosives on vulnerability were investigated. Results show that the limit penetration depth of Comp.B explosive is 200~250 mm at 25 ℃. The highest level of response for Comp.B explosive at -40, 25 and 70 ℃ are deflagration, explosion and deflagration, respectively. The level of reaction of bullet penetration to Comp.B explosive is restrained at high temperature or low temperature. The decrease of shear modulus strength of Comp.B charges makes the degrees of response to Comp.B explosives reduce.

Abstract:In view of the poor workability of explosive materials and its sensitivity to force and temperature shock, and using the ultrasonic vibration turning the MJ-9159 explosive simulants and digital confocal surface microscopic morphology measurements as the foundation of test, the ultrasonic vibration turning mechanism was studied and the effects of the common turning and the ultrasonic vibration turning mode with amplitude of 2, 3.4, 5 μm on the machined surface quality were compared and analyzed. The results show that ultrasonic vibration turning surface quality is better than that of common turning. Based on the stress wave effect, when the separate state of ultrasonic vibration turning is the speed 60 m·min^-1 and amplitude 5 μm, the turning surface quality is best.

Abstract:In order to evaluate the effect of ultrasonic vibration cutting (UVC) on cutting temperature(CT), UVC and conventional cutting(CC) tests on HMX based PBX explosive simulants were carried out. CT of machined surface and cutting tool nose were detected by infrared thermal imager in the machining process. Results show that CT of the two method all increase with the cutting speed, cutting depth and amount of feed. And the cutting temperatures of UVC are all higher than that of CC. The highest CT of UVC is 78.1 ℃, higher than that of CC by 31.3 ℃. The cutting heat of UVC is less than that of CC, and the dissipated heat of UVC is more than that of CC. The main reason for the augment of CT is the cumulation of excitation heat in UVC, which plays a decisive role in final CT. It is possible to obtain a higher, unaltered or a lower CT of UVC compared to CC.

Abstract:To improve the pump efficiency of Zr/KClO₄ pyrotechnic reagent used in Solid state laser pump sources, the carbon nanotubes (CNTs) with catalytic property, high specific surface area, strong adsorption capacity and high strength were introduced in pyrotechnic reagent Zr/KClO₄. The effect of carbon nanotubes on the thermal decomposition and light radiation performance of Zr/KClO₄(60/40) pyrotechnic reagent used in the pump sources was studied by differential thermal analysis technology and photoelectric detection technology. The results show that the addition of CNTs has a significant impact on the thermal decomposition characteristics and light radiation energy of Zr/KClO₄. With increasing of the CNTs, the combustion rate and exothermic quantity of the pyrotechnic reagent gradually increase, and the melting endothermic peak of the pyrotechnic reagent decrease and tend to disappear. However, the light radiation energies reveal the trend of firstly increases and then decreases. When the mass percentage of CNTs in the pyrotechnic reagent is 0.50%, the total radiation energy of the pyrotechnics can reach 1830 J·g^-1. The effective radiation energy within the three strong absorption bands of Nd: Yttrium Aluminum Garnet(YAG) laser gain medium, that is (590 ±10) nm, (750±10) nm and (808±10) nm, can be increased by 41%, 25% and 31%, respectively.

Abstract:To evaluate the effects of different additive on the luminous intensity of pyrotechnics composites containing KClO₄ and Al powder, the nano-CuO/CNTs composite particles were prepared by a boiling reflux precipitation method. Their structures and performance were characterized by transmission electron microscope (TEM), X-raydiffraction(XRD) and simultaneous DSC-TG apparatus(DSC-TG). The luminous intensity of pyrotechnics formula with different additive was tested. Results show that the CuO particles can be loaded on the surface of CNTs, and the average diameter of CuO/CNTs is 61.1 nm, and the size of loaded copper oxide particles is 8.8 nm, and its loading capacity is 30%. The luminous intensity of composite formulation containing nano-CuO/CNTs, Al and KClO₄ is better than that of the other ones containing single additive. Compared to the same mass ratio mechanical mixture formula containing CNTs, CuO, Al and KClO₄, the luminous intensity of composite formulation containing nano-CuO/CNTs composite, Al and KClO₄ is increased by 11.2%, indicating that the CuO/CNTs composite particles has stronger positive synergistic catalytic effect.

Abstract:Based on the fundamental principle of particle gradation, the Si and CuO powder with different particle sizes were prepared. The Si-CuO delay composition with different gradation specifications was prepared. The delay precision test of various delay compositions was carried out. Results show that better granularity distribution consistency for oxidant or combustible agent is favorable for enhancing delay precision of delay composition. Third-grade particle gradation of the oxidant and combustible agent is not favorable for enhancing dely precision of delay composition. The delay composition with second-grade particle gradation, which is closer to the optimum particle gradation.

Abstract:To study the lethality of azimuthal warhead, a fragment muzzle velocity formula used in limited angles of extension line opposite to azimuthal detonating point of azimuthal warhead was deduced, and tungsten cylinder fragment and tungsten sphere fragment azimuthal warheads were designed to validate the model by experiments. Results show the formula can be used to the calculation of azimuthal warhead. The designed azimuthal warhead velocity gain is 10.9% for tungsten cylinder fragment and 19.8% for tungsten sphere fragment. The muzzle velocity, sphere distribution density and killing probability of tungsten sphere fragment are better than those of the tungsten cylinder fragment.

Abstract:Fenton oxidation method was adopted to degrade the HMX production wastewater. Effect of H₂O₂ concentration, pH value, FeSO₄ concentration, temperature, reaction time and dosing mode of H₂O₂ on the removal efficiency of HMX and COD(chemical oxygen demand) were investigated. Results show that the suitable parameters are pH=3, temperature 20 ℃, dosing concentration of H₂O₂ 2 mol·L^-1, six times dosing mode, FeSO₄ concentrantion 0.05 mol·L^-1, the reaction time 1.5 h. Under this conditions, the COD removal rate and HMX removal rate separately reaches 88.8%, 91.58%. The BOD(biochemiacl oxygen demand)/COD of the HMX wastewater increases from 0.013 to 0.328, which meets the requirements of biochemical treatment.

Abstract:The progresses of study on the synthesis and performance of 3-azido-1, 2, 4-triazole and its derivatives, including N-alkylation derivatives, N-arylation derivatives, N-heterocylization derivatives, halogenations derivatives, metal complexes and other derivatives, were reviewed with 43 references.

Abstract:The researches on nano-energetic materials have become one of the hotspots in the fields of nano-materials and energetic materials as their excellent properties. The common methods to prepare the nano-energetic materials were briefly introduced, the existing self-assembled preparation methods of nano-energetic materials were analyzed and the new ideas to prepare the macromolecular self-assembly nano-energetic materials were proposed. The preparation of nano-materials based on self-assembly of macromolecules and co-assembly of nanoparticles with macromolecule were summarized. The analysis indicates that there are great applied prospect to prepare nano-energetic materials based on macromolecular self-assembly. But it is still in the exploratory stage and need further research both theoretically and experimentally in the future.

Abstract:Explosive and its trace detection technology has become one of research hotspots in the field of current international anti-terrorism. All kinds of sensors, such as surface acoustic wave sensors and ion mobility spectrum sensors, used to detect explosives, can not meet the requirements of practical application in the detection indicators. The graphene based explosive sensors with detection limit by 10^-10 have the advantages of fast response and high sensitivity and have gradually become the focus of research. In this paper, the superiorities of graphene in the sensor application were briefly analyzed. The progresses of study about graphene based explosive sensors, including electrochemical, surface enhanced Raman scattering (SERS), fluorescence resonance energy transfer (FRET), and electrochemical luminescence (ECL) sensors were emphatically introduced in recent years. The technical characteristics of existing grapheme based explosive sensors were summarized. Considering that the surface modification and functionalization of graphene and graphene oxide (GO), development of graphene hybrid materials with excellent performance and improvement of the detection sensitivity are the direction of future research.

Abstract:7-(3′-Amino-2′, 4′, 6′-trinitrophenyl)-amino-4, 6-dinitrobenzofuroxan was synthesized using 3-chloro-2, 4, 6-trinitrobenzenamine as primary material by self-reaction and azidcation with a total yield of 68%. Its structure was confirmed by MS, IR and ¹H NMR. Thermal behavior was studied by DSC and TG. Results show that its initial decomposition temperature is 245.6 ℃, and the mass loss due to overall reaction (150-400 ℃) is 63%.

Abstract:2, 3-Dihydro-1H-imidazo[4, 5-b]pyridin-2-one(1) was synthesized by ring-closing reaction using 2, 3-diaminopyridine as primary material. A novel compound 1, 3, 5-trinitro-2, 3-dihydro-1H-imidazo-[4, 5-b]pyridin-2-one(2) was obtained with it by nitration in the system of HNO₃/Ac₂O, with a yield of 44.6%. Their structures were characterized by ¹H NMR, MS and IR, and thermal behavior of compound 2 was studied by differential scanning calorimetry and thermogravimetry. Results show decomposition temperature of compound 2 is 153.0 ℃, and the mass loss due to overall reaction (130~450 ℃) is 55.5%, indicating poor heat stability of compound 2.

Abstract:Two energetic compounds——4-aminodifurazano[3, 4-b, e]pyrazine (ADFP) and 4, 8-diaminodifurazano[3, 4-b, e]pyrazine (DADFP) were prepared via N-amination reaction and their structures were characterized by IR, ¹H NMR, ¹³C NMR, MS and elemental analysis. The themal properties of ADFP and DADFP were analyzed by differential scanning calorimetry and thermogravimetry techniques. Results show that DADFP melts concomitantly with decomposition at 284.3 ℃. The melting point of ADFP is 218.1 ℃ and its first decomposition temperature is 247.1 ℃, which indicate that ADFP and DADFP have good thermal stability.

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